JACPOT XRB is a Target of Opportunity project, to be triggered by a detection of an outburst with an X-ray satellite (RXTE, SWIFT, INTEGRAL or MAXI), or, for the white dwarf system, on an AAVSO alert. On receipt of an alert, we will immediately begin monitoring with the VLA (northern hemisphere) or ATCA (southern hemisphere), and on detection of radio emission, the VLBA (nothern hemisphere) or LBA (southern hemisphere) will begin its monitoring campaign.

In 2009-2010, we monitored a white dwarf (SS Cyg), a neutron star (Aql X-1), and a black hole (H1743-322). In 2010-2011, we monitored a black hole system (MAXI J1836-194), as our target neutron star proved (4U 1820-30) too faint for VLBA monitoring. For the 2012-2013 campaign, we triggered VLA observations of a black hole system (Swift J1745-26); however, high telescope demand prevented VLBA monitoring. We are currently allocated time to monitor a black hole source in the northern hemisphere and southern hemisphere during 2013-2014.

16-Jun-2009: Radio flux density has dropped to around 0.3 mJy at 8.4 GHz, ending this phase of VLBA monitoring. VLA observations are ongoing as we await transition back to the hard state.

07-Jul-2009: Based on RXTE PCA data, the source appears to have transitioned or to be transitioning to the hard state (Kalemci et al., ATel 2112). High rms amplitude in from timing analysis combined with a hardness above 0.6 indicate the source is in the high state. VLBA observations have been retriggered.

06-Aug-2009: Based on all data, the source appears to have gone into quiescence. VLA/VLBA observations have been halted.